Isotopes - different number of neutrons

(pronounced ahy-suh-tohp)

All atoms of an element will have the same number of protons. However, atoms of the same element can sometimes have a different number of neutrons. These are called isotopes.

To remember the meaning of isotope use the following mnemonic:

Newts loved skating on ice, on top (isotope) but sometimes there were more skating and sometimes were less because they went for a swim.